Carbidopa — uses, dosing, side effects & the brands that sell it · pharmaranks
Carbidopa: uses, dosing, side effects & brands
Carbidopa is a medicine sold in the U.S. under 2 brand and generic names. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
By the pharmaranks editorial team·Reviewed against the FDA (openFDA label, NDC Directory & Enforcement) sources·How we research
Key facts
Available as
Tablet
Sold as
2 products — Carbidopa and Lodosyn
Prescription?
Prescription only
Generic available?
Yes
Typical price
about $21 for a 30-count supply
How carbidopa is dosed
From the FDA label for Carbidopa (application ANDA203261). Other carbidopa products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Whether given with carbidopa-levodopa or with levodopa, the optimal daily dose of carbidopa must be determined by careful titration. Most patients respond to a 1:10 proportion of carbidopa and levodopa, provided the daily dosage of carbidopa is 70 mg or more a day. The maximum daily dosage of carbidopa should not exceed 200 mg, since clinical experience with larger dosages is limited. If the patient is taking carbidopa-levodopa, the amount of carbidopa in carbidopa-levodopa should be considered when calculating the total amount of carbidopa to be administered each day. Patients Receiving Carbidopa-Levodopa Who Require Additional Carbidopa Some patients taking carbidopa-levodopa may not have adequate reduction in nausea and vomiting when the dosage of carbidopa is less than 70 mg a day, and the dosage of levodopa is less than 700 mg a day. When these patients are taking carbidopa-levodopa, 25 mg of carbidopa may be given with the first dose of carbidopa-levodopa each day. Additional doses of 12.5 mg or 25 mg may be given during the day with each dose of carbidopa-levodopa. Carbidopa may be given with any dose carbidopa-levodopa as required for optimum therapeutic response. The maximum daily dosage of carbidopa, given as carbidopa and as carbidopa-levodopa), should not exceed 200 mg. Patients Requiring Individual Titration of Carbidopa and Levodopa Dosage Although…
Carbidopa side effects
Carbidopa has not been demonstrated to have any overt pharmacodynamic actions in the recommended doses. The only adverse reactions that have been observed have been with concomitant use of carbidopa with other drugs such as levodopa, and with carbidopa-levodopa combination products. When carbidopa is administered concomitantly with levodopa or carbidopa-levodopa combination products, the most common adverse reactions have included dyskinesias such as choreiform, dystonic, and other involuntary movements, and nausea. Other adverse reactions reported with carbidopa when administered concomitantly with levodopa alone or carbidopa-levodopa combination products were psychotic episodes including delusions, hallucinations, and paranoid ideation, depression with or without development of suicidal tendencies, and dementia. Convulsions also have occurred; however, a causal relationship with concomitant use of carbidopa and levodopa has not been established. The following other adverse reactions have been reported with levodopa and carbidopa-levodopa combination products. These same adverse reactions may also occur when carbidopa is administered with these products. Body as a Whole: abdominal pain and distress, asthenia, chest pain, fatigue. Cardiovascular: cardiac irregularities, hypertension, myocardial infarction, hypotension including orthostatic hypotension, palpitation, phlebitis,…
Every carbidopa product we track (2)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Carbidopa, an inhibitor of aromatic amino acid decarboxylation, is a white to yellowish white powder, slightly soluble in water, very slightly soluble in ethanol (96%), practically insoluble in methylene chloride, with a molecular weight of 244.3. It is designated chemically as (–)-L-α-hydrazino-α-methyl-β-(3,4-dihydroxybenzene) propanoic acid monohydrate. Its molecular formula is C 10 H 14 N 2 O 4 •H 2 O and its structural formula is: Each tablet contains 25 mg of carbidopa USP (anhydrous equivalent). Inactive ingredients are magnesium stearate, microcrystalline cellulose and pregelatinized starch (maize). Tablet content is expressed in terms of anhydrous carbidopa which has a molecular weight of 226.3. chemical structure
Can you take carbidopa with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run carbidopa against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is carbidopa sold under?
We track 2 carbidopa-containing products in the U.S.: Carbidopa and Lodosyn. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does carbidopa come in?
Across the brands we track, carbidopa is currently marketed as tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic carbidopa?
Yes. Our catalog lists 1 generic carbidopa product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Has carbidopa been recalled?
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Who shouldn’t take carbidopa
Carbidopa tablets are contraindicated in patients with known hypersensitivity to any component of this drug. Nonselective monoamine oxidase (MAO) inhibitors are contraindicated for use with levodopa or carbidopa-levodopa combination products with or without carbidopa. These inhibitors must be discontinued at least two weeks prior to initiating therapy with levodopa. Carbidopa-levodopa or levodopa may be administered concomitantly with the manufacturer’s recommended dose of an MAO inhibitor with selectivity for MAO type B (e.g., selegiline HCl) (see PRECAUTIONS , Drug Interactions ). Levodopa or carbidopa-levodopa products, with or without carbidopa, are contra-indicated in patients with narrow-angle glaucoma.
Carbidopa drug interactions
Dyskinesia Carbidopa may potentiate the dopaminergic side effects of levodopa and may cause or exacerbate preexisting dyskinesia.
The FDA's Enforcement database lists 1 recall record whose product description mentions carbidopa. The most recent: Carbidopa, Levodopa, Entacapone Tablets, 25 mg/100 mg/200 mg, 100-count bottle,… (Oct 7, 2025). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.